Literature Review Example: Annotated and Explained

The examples on this page show what a strong literature review looks like in practice. Each is annotated to explain why specific choices were made: how sources are grouped thematically, how debates are framed, how gaps are identified, and how the review connects to the study it introduces.

For a full guide on how to write a literature review from scratch, see how to write a literature review.

What a Literature Review Is Supposed to Do

Before reading the examples, it helps to understand the purpose. A literature review is not a summary of every paper you read. It is an organized argument that:

1. Maps what has been studied on a topic and what conclusions the evidence supports
2. Identifies where evidence is limited, contradictory, or methodologically weak
3. Establishes the specific gap or debate that the current study addresses
4. Shows the reader that the author understands the field well enough to conduct credible research

Everything in the review should serve one of these four functions. A sentence that describes a paper without connecting it to the argument is padding.

Example 1: Literature Review for a Research Paper

This example is the length typical for a standalone research article or journal submission (approximately 600 to 900 words for the review section). The topic is social media use and adolescent mental health.

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[OPENING: Names the broad phenomenon and establishes why it matters]

Adolescent mental health outcomes have deteriorated across multiple measures over the past decade. US national surveys show that rates of persistent feelings of sadness or hopelessness among high school students increased from 26 percent in 2009 to 44 percent in 2023 (CDC, 2024). During this same period, smartphone ownership among teenagers rose from 23 percent to over 95 percent (Pew Research Center, 2023). The temporal overlap has fueled debate about whether widespread social media use is a contributing cause of worsening adolescent mental health or whether both trends reflect common underlying social conditions.

[THEMATIC SECTION 1: Presents the evidence for a relationship]

A substantial body of correlational evidence links social media use to negative mental health outcomes, particularly in adolescent girls. Twenge et al. (2018) analyzed data from over 500,000 adolescents and found that heavy social media users (more than 5 hours per day) were 66 percent more likely to report at least one suicide risk factor than those who spent no time on devices. Similarly, Kelly et al. (2019) found that social media use at age 13 predicted depressive symptoms at age 14, controlling for prior mental health status. A meta-analysis of 13 longitudinal studies found a small but consistent association between social media use and depression (Coyne et al., 2020), with effect sizes larger for girls than boys.

[THEMATIC SECTION 2: Presents the counterevidence and complicates the picture]

Other research challenges the interpretation that social media causes harm. Orben and Przybylski (2019) applied specification curve analysis to three large datasets and found that the effect of social media on adolescent wellbeing was statistically significant but practically small, approximately the same magnitude as wearing glasses or eating potatoes. Several experimental studies that randomly assigned adolescents to reduce social media use found modest improvements in wellbeing (Hunt et al., 2018) or no significant effects (Tromholt, 2016), suggesting that the relationship may not be straightforwardly causal.

[METHODOLOGICAL CRITIQUE: Explains why existing evidence is insufficient]

A critical limitation of this literature is its near-exclusive reliance on self-reported measures of both social media use and mental health. Time diary studies consistently show that self-reported screen time overestimates actual use by 40 to 60 percent (Ellis et al., 2019). Additionally, most studies treat social media use as a single undifferentiated variable, combining passive consumption (scrolling without interacting) with active use (posting, messaging, commenting), despite evidence that these behaviors have distinct psychological profiles. Fardouly and Vartanian (2015) found that passive consumption drove social comparison whereas active engagement did not, suggesting that aggregate social media use measures may obscure the most important distinctions.

[GAP STATEMENT: States what is missing and what this study addresses]

No published longitudinal study has examined whether the type of social media use (passive versus active) differentially predicts depressive symptom onset, while also controlling for baseline depressive status using a validated clinical measure rather than a single-item self-report. The current study addresses this gap by analyzing 24 months of passive-measurement social media activity data alongside quarterly PHQ-9 scores in a sample of 312 adolescents aged 12 to 16.

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What this example demonstrates:

• Sources are grouped thematically (evidence for, counterevidence, methodological problems), not listed chronologically
• Each section advances the argument toward the gap; no section is purely descriptive
• The gap statement is specific: it names what is missing and what the current study does differently
• Citations include meta-analyses and large-n studies, not just individual papers

Example 2: Dissertation Chapter Literature Review

A dissertation literature review is longer (typically 20 to 50 pages) and covers the field more comprehensively. The following is a condensed example of how one sub-section of a chapter might read. The topic is school funding equity and student achievement.

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[SECTION HEADER: Thematic label for this subsection]

The relationship between school spending and academic outcomes

[OPENING CLAIM: States the argument for this section]

The question of whether additional school funding improves student outcomes was considered settled for much of the 1990s following Coleman et al.'s (1966) landmark finding that school resources explained little variation in student achievement once family background was controlled. Subsequent decades of reanalysis have substantially revised this conclusion.

[LITERATURE SYNTHESIS: Groups studies by what they show, not when they were published]

Jackson, Johnson, and Persico (2016) used natural variation in school spending driven by court-ordered finance reforms as an instrument to isolate causal effects, finding that a 10 percent increase in per-pupil spending throughout the school years led to 7 percent higher adult wages, lower rates of adult poverty, and higher educational attainment. Importantly, effects were largest for students from low-income families. Lafortune, Rothstein, and Schanzenbach (2018) found that post-1990 court-ordered funding reforms improved test scores in low-income districts, with effects accumulating over time. A meta-analysis by Greenwald, Hedges, and Laine (1996), reanalyzing the Coleman data with improved methods, found positive relationships between resource inputs and student achievement that the original analysis had obscured.

[QUALIFICATION: Acknowledges limits of the affirmative evidence]

This evidence is not without qualification. Hanushek (1997, 2003) argues that the relationship between spending and outcomes is highly heterogeneous: some spending increases improve outcomes, while others do not, depending on how funds are allocated. Experimental evidence from the Tennessee STAR project demonstrates that class size reduction (a resource-intensive intervention) improves outcomes for students in grades K-3, but the same effect has not replicated as clearly in subsequent observational studies at scale. The productive use of additional funds, not their amount alone, determines whether investment produces gains.

[CONNECTION TO DISSERTATION GAP]

The existing literature demonstrates that school spending can improve outcomes but does not yet adequately explain the mechanisms: which types of spending, on which student populations, and under which governance conditions produce the most reliable improvements. Chapters 3 and 4 of this dissertation investigate two of these mechanisms by examining whether the effects of court-ordered funding reforms are moderated by district-level governance capacity and state accountability systems.

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What this example demonstrates:

• Subsections have clear thematic headers
• The review engages with methodological debates (how to establish causation in education research) rather than just reporting findings
• The review ends by connecting directly to the dissertation's specific contribution
• Both affirmative evidence and qualifications are presented and synthesized rather than cherry-picked

Common Mistakes the Examples Avoid

Annotating rather than synthesizing. Weak: "Smith (2020) found X. Jones (2021) found Y. Brown (2022) found Z." Strong: Grouping Smith, Jones, and Brown under a shared finding and discussing what their combined evidence shows, where they diverge, and what remains uncertain.

Chronological organization. Organizing by publication date ("First, researchers in the 1990s... Then, in the 2000s...") does not build an argument. Thematic organization builds an argument.

Describing papers rather than evaluating them. A literature review that only says what papers found, without assessing their methodological quality or how they relate to each other, does not demonstrate command of the field.

Vague gap statements. "More research is needed on this topic" is not a gap statement. "No study has examined X in population Y using method Z" is.

Including sources that do not serve the argument. Every paragraph should advance the reader toward understanding what is known, what is contested, and what your study adds. Sources that are interesting but not relevant to these functions should be cut.

How Long Should a Literature Review Be?

For further guidance on writing each section, see how to write a literature review. For writing the full dissertation chapter that follows, see how to write a PhD dissertation. For the abstract that introduces the full work, see how to write an abstract.